Railway-traffic-controlling apparatus



Feb. 9 1926.

R. A. MCCANN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May i5, 1924 Il n . INVENTOR 3 ,Qa-MM amm.

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Patented Feb. 9, il.

unirte srArEs 1,572,545 PATENT ortica.

RONALD A. MCCANN, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO THE UNION SWTCH & SIGNAL COMPANY, GF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENN SYLVAN IA. i

RALW'AY-TRAFFIC-CONTROLLING APPARATUS;

Application led May 15, 1924.

fo all 1072.071 t may concern.'

Be it known that l, RONALD A. MCCANN, a citizen of the United States, residing at Swissvale, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Railway-filraiiic-Controlling Apparatus, of which the following-is a speciiication.

My invention relates to railway traffic controlling apparatus, and particularly to apparatus of the type comprising train'carried governing means controlled by energy received from the trackway.

Apparatus embodying my invention is particularly adapted for use on two or more parallel tracks where it is desirable, for purposes of safety, to limit the number of trains which may simultaneously occupy a given territory, such for example, as the territory in the middle of a bridge span, a railway station, or a gauntlet track.

I will describe Vtwo forms and arrangements of apparatus embodying my invention, and will then point out the Vnovel features thereof in claims.

In the accompanying drawing,'Fig. l is a diagrammatic view showing one form of trackway apparatus embodying my inventtion. Fig. 2 is a diagrammatic view showing a modification of the apparatus shown in Fig. l and also embodying my invention.

Similar reference charactes refer' to similar parts in both views.

Referring. iirst to Fig. l, the reference characters l and la designate the track rails oi a stretch of railroad track X, and the reference characters Q- and 2a designate the two rails of a second track Y, parallel with track X. These two tracks comprise a restricted territory which should be occupied by but one train at a time, and as here shown this restricted terriory is formed by a gaunlet made up of the two tracks.

As here shown, traiiic normally moves over each track X and Y in the direction indicated by the arrow, and the rails of each track are divided into a plurality of successive track sections by means of insulated joints 3. X and one section C-D of track Y are shown in the drawing, and the gauntlet portion is located within these sections.

Each section of each track is provided with a trackway signal designated by the Only one section A-B of track Serial No. 713,453.

reference characted S with anexponent corresponding to the location. Each such signal S is here shown as a three-position semaphore signal located adjacent the entrance end of the associated section, though this particular form and location are -not essential. the usual and well known manner by means responsive to traiiic conditions in advance by means forming no part of my present invention and `hence omitted from the drawing for the sake of simplicity. It is suiiicient to say that each signal is controlled so that when the associated section is occupied, the signal indicates stop; when the corresponding section is unoccupied and the next section in advance is occupied, the signal indicates caution; and when the corresponding section and the section next in advance are both unoccupied, the signal indicates proceed.

Each of thesignals SA and SC is provided with a circuit controller designated by the These signals are controlled in reference character K with a suitable exponent arranged to be closed when the corresponding signal indicates proceed or caution, but to be open when" such signal indicates stop.

Each sectionis also provided with a track circuit including a track relay designated by the reference character `R with a suitable ldistinguishing exponent and connectedacross the rails adjacent the entrance end of the section and a suitable source of track circuit current here shown as a track battery designated by the reference character G with an appropriate exponent and connected across the rails adjacent the exit end of the section. To complete and isolate these track circuits the frogs formed where rail la crosses rail 2 are separated from the rest of rail l;l by means of insulated joints 3a and rail 1a is made electrically continuous past the'breaks so formed, by means of auxiliary cables 4.

Means are also provided for supplying'to each section an alternating train controlling current. For this purpose I provide each of sections A-B and C-D with a track transformer designated by the reference characterT with an exponent corresponding to the location and having a secondary winding 5 interposed between one rail of the associatedsection and the corresponding track battery G. An impedance '('is interposed between the secondary 5 of each track transformer and one rail of the corresponding section in the usual manner,

Alternating current is at times supplied to transformers TA and TC from a transformer Q, the primary 9 of which is constantly supplied With V alternating current from some suitable source not shown in `the drawing. The primary .circuit for transferir-ier TC is closed when relay yRB is energized and signal .SC indicates proceed or caution, under which conditions current flows from t-he secondary .8 `of transformer Q, throughwire 1.0, front .Contact ll of track relay RB, wire l2, circuit controller KC, operated by signal SC, vire 13, primary 6 of transformer TC, and wires lil and l5 hack to s condary 8 of'transformer Q. A

Then relay RD energized and signal SA .indicates proceed or caution, current is supplied to transformer TA Aover a circuit which may he traced from secondary 8 .of transformer Q, through Wires l@ and 16., front contact 17 of relay RD, Wire 18, circ-.uit .coi'itroller KA oper-ated hy signal SA, Wire 18A, primary (i y'of'transformer TA, and ivire l hack .to secondary 8 of transformer Q.

Before .explaining the operation of the apparatus it should he pointed out that the trxackway apparatus shown .in Fig, l is intended for ycio-operation With train carried verning means in such manner that when thetrain occupies a `stretch of track which is supplied with :alternating train controlling current a proceed indication is .received on board the train, but when such supply is interrupted a lstop indication is received on the train.

is :shown in the drawing both signals S" and SC are indicating proceed and .lio-th sections AWB and C-D 'are unoccupied. lief lays RD ad. RB are therefore both enervgized `by current from the associated track batter-ies G. 1li-s .a result,` transformers TA .and TC are looth supplied with lalternating current andy sections A-'B and C--B are each supp-lied ivi-th train controllingcurrent. I will novi7 assume that a train on track X enters section AeB.. `Relay RB is .1de- -enengized as soon as the train passes point- B. The circuit for transformer TC is therefore interruptedand the supply kof train controlling current to section .C-D is therefore discontinued. A train entering section C-D `would therefore receive a stop indication. The -de-energifz-ati-on of relay RB does not affect the supply of train governing .current to section 1 -B, and so the lirst :train is permitted to proceed through :the sec-tion under a proceed indication. As the train enters the section to the left `of point A, signal SA Vmoves to the stop position. The circuitis then interrupted for transformer TA, thus .causing a following train entering section A-B on track X to receive a stop indication. As the first train moves out of section AL-B, if section A-B is unoccupied, relay RB 'becomes energized, thus completing the circuit `for transformer TC, soy that another train on track Y entering section (li-D would receive a proceed indication.

In the modification shown in Fig. 2, the track relays RD and RB are alternating .current'relays, and the transforniers TA .and TC constitute sources .of track circuit current as well as of train controlling current.

Means are also provided for .supplying to the rails in parallel of sections A--B and C-D, a .curient which I 4shall hereinafter term a 'A loop current. For this .purpose 'I provide each .of these sections with an iinpedance 19 .connected across the rails adjacent .the exit .end of .the section, `and a similar impedance 20 .connected across the rails adjacent the .entrance .end .of the section. The .connections for the `loop .circuit .are then vmade to the mid-points of these impedances. Loop current is .supplied to each of the sections A'B and. .C--D by .a loog Vtransformer associated with such section and designated by the reference character L with an .exponent corresponding to the location. VThe primary 22 of each loop transformer is .constantly supplied with al` ternating Vcurrentfrom secondary S of transformer Q. y

The loop circuit for .section C-D may be traced froinsecondary'2l .of transformer LC, through Wire 28, front .contact 2l of .relay RB, Wire 25, 'impedance 20 in section C-D, through the rails .of the section in parallel to impedance 1.9., Wire 26., circuit controllei.' 1

KC `operated by signal SC, and Wire 9.7 back to transformer LC. This circuit is closed only when relay RB is energized andsignal SC indicates proceed or caution, under which conditions loep .current is supplied to section IC-fl). When signal SA is at proceed o1' caution vand relay RD is .energizedl 'current flows from secondary 2l of loop transformer LA, through ivire 28, .front contact 29. of relay RD, wire `30.' impedance 210 in section .fr-B, through both rails of the .section in parallel .to impedance 19, ivi-re 3l, circuit controller KA operated hy signal SA, and wire 32 hack to transformer LA. Under these .Conditions loop .current 'is supplied to the rails of section A.-B.

The trackivay apparatus shown in 2 is intended for cooperation with train carriedgoverning means so arranged that when the train. voccupies a section of track that is supplied with 4alternating track circuit current `and .also with .loop current'the train .receives a proceed indication,- hut when the supply .of either of suoli .currents 1s interf rupted, the train receives a stop indication.

Track circuit 1s at all times supplied to both sections. It will be noticed however that when a tram occupies section A-B,

the resulting dei-energization of relay RB causes the loop current to be discontinued in section C-D and hence will cause a stop indication to be received by a train in section C--D. Similarly, a train in section C-D will cause a stop indication on a train in section A-B It' a train is occupying one of the sections shown in the drawing', such as section A l, a second train following' the first into the section will be deprived ot track circuit current as a result of the shunting `action of the wheels and axles of the iii-st train and hence the second train will receive a stop indication.

It'should also be pointed out that when either of signals SA or SC is at stop, the opening of thev corresponding loop circuit will cause a stop indication on a train pro ceeding through the gauntlet on the associated track.

It will be plain that, with` both forms ot apparatus embodying my invention, a train in either of the sections A-B or B-C will cause a stop indication to be received on a train occupying' the other section.

Although I have herein shown and described only one formof trackway apparatus embodyingmy invention, it is understood that various changes and modications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

VHaving thus described my invention, what I claim is:

l. In combination, two parallel sections ot railway track comprising a. restricted territory, means for connecting a source of train controlling current across the rails of each section, and means for interrupting the supply of such current to each section when the other section is occupied.

2. In combination, two parallel sections ot railway track comprising al restricted territory, means for supplying train controlling current to each" section, a track circuit for each section including a source of track circuit current and a track relay. and means for interrupting the supply of such train controlling current to each section when the other section is occupied.

3. In combination, two parallel sections of railway track comprising a restricted territory, means Jfor supplying train controlling current to each section, a track circuit for each section including a source ot track circuit current and a track relay, and means controlled by each track relay and arranged when the corresponding section is occupied for interrupting the supply of train controlling current to the other section.

Li. In combination, two parallel sections of railway track, a track circuit for each section including a track relay and a source ot' track circuit current, means for supplying each section with train controlling current, and means tor one Asection controlled by trafHc conditions in the other section for at times interrupting the supply of train controlling current to said one section.

5. In combination, two parallel sectionsV ot railway tract, a track circuit foreach section including a track relay and a source of track circuit current, a transtormer tt'or supplying train controlling current to one of said sections, and means responsive to traffic conditions in the other section for controlling the supply of current to said transformer.

G. In combination, two parallel sec-tions ot railway track, a track circuit for each section including a track relay and a source of track circuit current, and a transtormer con trolled by the track relay for one of said secs tions for supplying train controlling current to the other section.

7. In combination, two parallel sections of railway track con'iprising a restricted territory, means controlled by' traiiic conditions in advance for supplying each section with train controlling current, and means for each section responsive to traffic vconditions in said section for at times interrupting the supply of train controlling` current to the other section.

8. In combination, two parallel sections ot railway track comprising a restricted territory, a source ot track circuit current for each section, a track transformer for each section connected across the rails of the section and controlled by traiiic conditions in advance, and means for each section responsive to traiiic conditions in the associated section for at times controlling the track transformer tor the other section.

9. In combination, two parallel sections ot railway track comprising a restricted territory, means for constantly supplying alternating track circuit current across the rails ot each section, track relays for each section connected across the rails of the corresponding section, and means controlled by each track relay for at times supplying loop current to the rails of the other section.

10. In combination, two parallel sections of railway track, a separate source of alternating track circuit current constantly connected across the rails of each section, a

rtrack relay connected across the rails of each section, means for supplying loop current to eaclr section, and means controlled by the track relay for each section for at times interrupting the supply of loop current to the rails oi the other section.

li. VIn combination, two parallel sections oi railway track, a separate source of alter-A nating track circuit current constantly connected with the rails-of each section, meansfor supplying-loop current to-each section, andy means controlled by the track relay for each section for at times interrupting the supply of loop current to the rails of the other section.- Y

l2. ln combination, two-parallel sections of railway track, means tor supplying track Circuit current to one section', and means res-ponsii-'e to trailic conditions in theothor section tor at tiincssupplying. loop current to said one sect-ion. -v

'l1-. ln combination, two parallel sec-ti ns o'li railway trackcomprising a restricted territory, a source of alternatingcurrent for cach sectionconstantly connected across the rails of the section, a track relay for' each section connected across the rails ot such section, means for. ach section controlled by traffic conditions ink advance ot the section 'for supplying loopcurrent to the section, andt means controlled by each track relay toi' at times interrupting the supplyof loop current to the otherY section.

1 4; In combination, two parallel sections et railway track comprisingy a restricted territory, a source of alternating current for each section constantly connected across the rails ot the section,.a track relay for each section' connected across the rails ot such section, means tor cach section controlledby tratlic. conditions in advance oit-the section for supplying'loop current to the section", and means controlled by each. track relay and arrangedwhentlie associatedsectionis occupied to interrupt thesupply of loop current to the other section.

l5. In combination, two-parallel sections ot railway track. comprising a? Siestricted territory, a track circuit tor each section, and!ati-aincontrolling circuit tor each sectionincludingat least-'one rail ofthe section and controlled by tratficr conditions in the other section. A

16; In combination, two-parallel sections of, railway track comprising. a restricted for each track controlled'by` traffic condi-- tions on the other track within said territory for supplying` train controllingcurrent to the-associated track. n y

18. In combination, two parallel stretches ot railway track, arestrictcd territory containing at least a part of reach stretch, a

track circuitfor each stretch,- means for supplying train controlling current toeach stretch,y and means .tor interruptingthe supply ot such current to each stretch when a train occupies the other stretch `within the limits ot the restricted-territory.

19. ln combination, a railway having-two parallel tracks,.a restricted*'territory containing parts of both tracks, a trackF circuit for each track, means for supplying train controlling current to the rails of each section 'for controlling'trains through-said restricted territory, and means responsive? to traiiic conditions on ,one track within. the limits of said territory tor controllingthe sugply of train-controlling current to that portionof the other track within the limits of said territory. i i

20. ln combination, two parallel sections ot railway track comprising a restricted territory, a train controlling loop circuit-for `each section including a souice otcurrent the terminals ot which are connected with at leastv one rail adjacent the two ends-ot the section, and means for interrupting 'the loop circuit tor each section when-the other section is occupied. 4

ln testimony whereof I valinmy signature.

RONALD A.. Mec/ANN, 

